Physical Sciences and Mathematics Commons^™

Modeling Fecal Bacteria In Oregon Coastal Streams Using Spatially Explicit Watershed Characteristics, Paul Bryce Pettus

Dissertations and Theses

Pathogens, such as Escherichia coli and fecal coliforms, are causing the majority of water quality impairments in U.S., making up ~87% of this grouping's violations. Predicting and characterizing source, transport processes, and microbial survival rates is extremely challenging, due to the dynamic nature of each of these components. This research built upon current analytical methods that are used as exploratory tools to predict pathogen indicator counts across regional scales. Using a series of non-parametric methodologies, with spatially explicit predictors, 6657 samples from non-estuarine lotic streams were analyzed to make generalized predictions of regional water quality. 532 frequently sampled sites in …

Scenario Development And Analysis Of Freshwater Ecosystem Services Under Land Cover And Climate Change In The Tualatin And Yamhill River Basins, Oregon, Robert Wesley Hoyer

Dissertations and Theses

Humans make decisions within ecosystems to enhance their well-being, but choices can lead to unintended consequences. The ecosystem services (ES) approach supports decision-making that considers all environmental goods and services. Many challenges remain in the implementation of the ES approach like how specific ES vary through space and time. We address this research problem using the Tualatin and Yamhill river basins in northwestern Oregon as a study area. Freshwater ES are quantified and mapped with the spatially-explicit ES modeling tool, Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST). In chapter II, we develop a simple urban land cover change modeling …

Soil Development And Vegetation Response To Removal Of A Small Dam, Lassen Volcanic National Park, California, Stephanie Kay Rohdy

Dissertations and Theses

Dam removal is increasing as dams age, yet little is understood about the pedogenic response to dam removal. This study reports on the edaphic changes of reservoir sediments and vegetation cover one year following removal of a small earthen dam in Northern California. In August 2012, I sampled surface sediments from the former Dream Lake reservoir in Lassen Volcanic National Park, and compared their physical and chemical properties with soil samples from two reference sites. I also estimated percent cover of vegetation in the former reservoir and reference sites. My results show that the reservoir was under reduced conditions, as …

Evaluation Of Phase Change Materials For Cooling In A Super-Insulated Passive House, Jeffrey Stephen Lauck

Dissertations and Theses

Due to factors such as rising energy costs, diminishing resources, and climate change, the demand for high performance buildings is on the rise. As a result, several new building standards have emerged including the Passive House Standard, a rigorous energy-use standard based on a super-insulated and very tightly sealed building envelope. The standard requires that that air infiltration is less than or equal to 0.6 air changes per hour at a 50 Pascal pressure difference, annual heating energy is less than or equal to 15kWh/m2, and total annual source energy is less than or equal to 120 kWh/m2. A common …

The Role Of Wood Microsites At Timberline-Alpine Meadow Borders For Conifer Regeneration, Adelaide Chapman Johnson

Dissertations and Theses

This research aimed to determine whether wood microsites ("nurse logs"), which are regeneration sites in Pacific Northwest (PNW) subalpine forests, supported regeneration at timberline-alpine meadow borders. Upward advance of forests and conifer invasion into alpine meadows, which may be occurring in conjunction with climate warming, have gained worldwide attention. Successful alpine meadow seedling regeneration depends on suitable substrate availability, or microsites, for seedling establishment. To better understand factors associated with wood microsite occurrence, mechanisms of wood input were determined and four specific hypotheses were posed to assess: (1) seedling density and seedling survival; (2) growing season length, summer mean growing …

Natural Area Stewardship Volunteers: Motivations, Attitudes, Behaviors, Corinne Handelman

Dissertations and Theses

To better understand the value of those who engage in environmental stewardship of natural areas, we studied volunteer steward's motivation to participate, their sustainable behaviors and attitudes toward stewardship-related constructs. Specifically, we designed and conducted a survey of volunteers who work as stewards in urban natural areas in Portland, Oregon. We hypothesize that as volunteer frequency increases: participants will be more motivated to participate for environmental reasons, volunteers will be more likely to feel a strong connection to the stewardship site, participants will be more likely to engage in public pro-environmental behaviors, and their level of environmental literacy will increase. …

Social-Ecological Dynamics Of Coral Reef Resource Use And Management, Sarah J. Freed

Dissertations and Theses

This dissertation investigates social and ecological factors that facilitate effective management of coral reefs as social-ecological systems. Meta-analytical and field-based methods were employed to examine current management challenges and identify strategies that improve management effectiveness and coral reef health. A meta-analysis was used to evaluate biological indicators of reef health in relation to the types of fishing regulations in place (no-take areas, gear restriction areas, and periodic closures) and the actor groups (community-based, co-management, state, private) involved in management efforts for coral reef fisheries throughout the world. Other than enhancement of fish biomass within no-take areas that was significantly greater …

Characterization Of The Shallow Subsurface Geohydrology Of The Ni-Les'tun Unit On The Bandon Marsh National Wildlife Refuge, Christopher Madison Beard

Dissertations and Theses

The Bandon Marsh is a large marsh restoration project located in southwest Oregon. The land has been previously used for dairy farms and much of the marsh was used for cattle grazing. The goal of the restoration is to recreate a natural habitat for shorebirds and fish. The purpose of this thesis is to gather and analyze data on the geology of the marsh and both ground and surface water quality to evaluate its ability to support biology.

The US Fish and Wildlife Service began restoration on the Bandon marsh in 2005. Research on the Ni-les'tun Unit began in that …

Arsenic Mobility And Compositional Variability In High-Silica Ash Flow Tuffs, Courtney Beth Young Savoie

Dissertations and Theses

Volcanic rocks typically have only low to moderate arsenic concentrations, none-the-less, elevated levels of arsenic in ground waters have been associated with pyroclastic and volcaniclastic rocks and sediments in many parts of the world. The potential for arsenic leaching from these deposits is particularly problematic as they often comprise important water-bearing units in volcanic terrains. However, the role that chemical and mineralogical variations play in controlling the occurrence and mobility of arsenic from pyroclastic rocks is largely unexplored.

This study uses chemical and X-ray diffraction data to characterize and classify 49 samples of ash-flow tuffs, and 11 samples of tuffaceous …

Preserving Nature Through Film: Wilderness Alps Of Stehekin And The North Cascades, 1956-1968, Nicolas Timothy Bergmann

Dissertations and Theses

On March 22, 1958 David Brower's film Wilderness Alps of Stehekin premiered to an audience of conservationists in Seattle, Washington. Almost two years in the making, the thirty-one minute film advocated the preservation of nature in Washington's North Cascades through the creation of a national park. Over the next decade, Wilderness Alps of Stehekin became the most influential publicity tool in the struggle to preserve the North Cascades. Because of the region's geographic isolation, the film was the first time many people throughout the nation were exposed to the scenic grandeur of the area. Images of craggy peaks and colorful …

Air-Quality And Climatic Consequences Of Bioenergy Crop Cultivation, William Christian Porter

Dissertations and Theses

Bioenergy is expected to play an increasingly significant role in the global energy budget. In addition to the use of liquid energy forms such as ethanol and biodiesel, electricity generation using processed energy crops as a partial or full coal alternative is expected to increase, requiring large-scale conversions of land for the cultivation of bioenergy feedstocks such as cane, grasses, or short rotation coppice. With land-use change identified as a major contributor to changes in the emission of biogenic volatile organic compounds (BVOCs), many of which are known contributors to the pollutants ozone (O₃) and fine particulate matter …

Climate Change Impact On The Spatio-Temporal Variability Of Hydro-Climate Extremes, Mohammad Reza Najafi

Dissertations and Theses

The rising temperature of the earth due to climate change has shown to alter the variations of hydro-climate variables, including their intensities, frequencies and durations. Extreme events such as floods are, in particular, susceptible to any disturbances in climate cycles. As such it is important to provide policymakers with sufficient knowledge about the probable impacts of climate change on hydrologic extremes and most importantly on floods, which have the highest impacts on the societies. For this reason analysis of hydro-climate extremes is commonly performed using data at each site (or grid cell), however due to the limited number of extreme …

Climate Change Impacts On Precipitation Extremes Over The Columbia River Basin Based On Downscaled Cmip5 Climate Scenarios, Ghulam Hussain Dars

Dissertations and Theses

Hydro-climate extreme analysis helps understanding the process of spatio-temporal variation of extreme events due to climate change, and it is an important aspect in designing hydrological structures, forecasting floods and an effective decision making in the field of water resources design and management. The study evaluates extreme precipitation events over the Columbia River Basin (CRB), the fourth largest basin in the U.S., by simulating four CMIP5 global climate models (GCMs) for the historical period (1970-1999) and future period (2041-2070) under RCP85 GHG scenario.

We estimated the intensity of extreme and average precipitation for both winter (DJF) and summer (JJA) seasons …

Extending Technology Roadmap Through Fuzzy Cognitive Map-Based Scenarios: The Case Of The Wind Energy Sector Of Pakistan, Muhammad Amer

Dissertations and Theses

In this modern era, energy is a key element required for sustainable development and prosperity of a society. Pakistan is an energy deficient country facing problems due to the shortage of over 4000 MW of electricity. The national energy sector is heavily dependent on imported fossil-fuel resources. The energy crisis is negatively affecting all economic and business activities, and it is widely recognized as a severe obstacle to growth and poverty reduction in the country. Establishment of wind farms can help to overcome the energy crisis.

In this research, a national level wind energy roadmap is developed through scenario planning. …

Application Of Gis And Spatial Analysis Of Golden Eagle Fatalities Caused By Wind Turbines At The Altamont Pass Wind Resource, Andrew James Pinger

Dissertations and Theses

The Altamont Pass Wind Resource Area (Altamont) near Livermore, California is the oldest and largest wind farm in the United States. It is known as a location of high avian mortality, especially for diurnal raptors such as the Golden Eagle (Aquila chrysaetos). Using the avian monitoring data collected at Altamont for over thirteen years (1998-2003, 2005- 2011), records were analyzed of 134 golden eagle deaths caused by wind turbine collisions. All wind turbines present during the same temporal range were characterized according to turbine variables, and geographic placement characteristics. Values of turbines that killed golden eagles were compared to values …

Statistical Analysis Of Stormwater Device Testing Protocols In Portland, Oregon, Zahra Kavianpour Isfahani

Dissertations and Theses

Stormwater treatment is commonly performed with a combination of approaches including the utilization of natural systems and engineered devices. Before using a proprietary treatment instrument it is required to verify its performance and efficiency in reducing different pollution components including the TSS. Different states have developed strategies and regulations for accepting new instruments. In this thesis the stormwater management plan of the City of Portland, Oregon(2008), is analyzed in order to improve the current regulations. These rules apply to new technologies which are proposed by vendors to be used in Portland's stormwater treatment plans. Each requirement which should be met …

Effects Of Hru Size On Prms Performance In 30 Western U.S. Basins, Madeline Olena Steele

Dissertations and Theses

Semi-distributed hydrological models are often used for streamflow forecasting, hydrological climate change impact assessments, and other applications. In such models, basins are broken up into hydrologic response units (HRUs), which are assumed to have a relatively homogenous response to precipitation. HRUs are delineated in a variety of ways, and the procedure used may impact model performance. HRU delineation procedures have been researched, but it is still not clear how important these subdivision schemes are or which delineation methods are most effective. To start addressing this knowledge gap, this project investigated whether or not HRU size has a significant effect on …

The Production Of Organic Nitrates In Portland Oregon And The Columbia River Gorge, Holly Ann Neill

Dissertations and Theses

This work studied the production of aerosol-phase organic nitrates in both Portland and the Columbia River Gorge (CRG). Ozone and NO_x species were investigated for correlation with organic nitrate aerosol, as they function as precursors to the production of organic nitrates. These ambient gas-phase measurements were collected in the same locations as high-volume (Hi-Vol) filters samples, in an urban and rural gorge setting to investigate correlations at the origin of the pollution plume and downwind. A novel Soxhlet extraction method for Hi-Vol filters was developed based on literature and EPA standard methods. Analysis for nitrate production was done by …

Effects Of Increased Nitrogen Deposition On The Dominance Of Hedera Helix In The Pacific Northwest, Bianca Christine Dolan

Dissertations and Theses

Increased nitrogen deposition has been shown to promote the dominance of invasive species, and nitrogen deposition rates have steadily increased in most of the Western United States in recent years due to population increases. The purpose of this study was to determine if increased rates of nitrogen deposition are contributing to the success of Hedera helix in the Pacific Northwest. Plots were established in Lesser Park in Portland, Oregon and received monthly treatments of ammonium nitrate for one year. Growth, measured as change in percent cover, was compared between treated and untreated plots for both H. helix and native species. …

Green Mind Gray Yard: Micro Scale Assessment Of Ecosystem Services, Erin Jolene Kirkpatrick

Dissertations and Theses

There is a spatial mismatch between the size of the area where people are living and the extent of land needed to ecologically support developed areas. More people are living in urban areas than any time in history, and the resources need to support cities have had to expand to try and meet the demands of increasing urban populations. However, areas of opportunity exist for urban areas to begin to positively contribute towards the available resources in a region. Because a large portion of urban areas is within private control, gaining a baseline understanding of how residents interact with ecosystem …

Mechanisms Of Methane Transport Through Trees, Ellynne Marie Kutschera

Dissertations and Theses

Although the dynamics of methane (CH₄) emission from croplands and wetlands have been fairly well investigated, the contribution of trees to global methane emission and the mechanisms of tree transport are relatively unknown. Methane emissions from the common wetland tree species Populus trichocarpa (black cottonwood) native to the Pacific Northwest were measured under hydroponic conditions in order to separate plant transport mechanisms from the influence of soil processes. Roots were exposed to methane enriched water and canopy emissions of methane were measured using a canopy enclosure. Methane accumulation in the canopy was generally linear and the average canopy …

A 30-Year Record Of The Isotopic Composition Of Atmospheric Methane, Doaa Galal Mohammed Teama

Dissertations and Theses

Methane (CH₄) is one of the most important greenhouse gases after water vapor and carbon dioxide due to its high concentration and global warming potential 25 times than that of CO₂ (based on a 100 year time horizon). Its atmospheric concentration has more than doubled from the preindustrial era due to anthropogenic activities such as rice cultivation, biomass burning, and fossil fuel production. However, the rate of increase of atmospheric CH₄ (or the growth rate) slowed from 1980 until present. The main reason for this trend is a slowdown in the trend of CH₄ sources. …

Map-Based Probabilistic Infinite Slope Analysis Of The Stephens Creek Watershed, Portland, Oregon, Ryan Andrew Cole

Dissertations and Theses

The Stephens Creek Watershed in southwest Portland, Oregon was chosen by the city as a pilot project for urban stream restoration efforts, and the infiltration of stormwater was identified as a potential restoration strategy. The Stephens Creek Watershed has historically been known to be unstable during high precipitation events (Burns, 1996), and the need to address the response of slope stability to anthropogenically-driven changing groundwater conditions is the focus of this study. Airborne light detection and ranging (LiDAR) and geotechnical data from the City of Portland were employed to create a high resolution (0.84 m2) physics-based probabilistic slope stability model …

Sustainable, Affordable Housing For Older Adults: A Case Study Of Factors That Affect Development In Portland, Oregon, Alan Kenneth Delatorre

Dissertations and Theses

Portland, Oregon, is considered to be a leader in sustainable development. Government agencies, nonprofit organizations, and businesses have been innovators in policymaking and practice that is aimed at creating a more sustainable city. Despite population aging, little is known about how or whether planners and developers consider older persons in terms of sustainable development. Thus, this study examined the case of sustainable, affordable housing developed for low-income adults aged 55 and older. Interviews with 31 key informants were conducted in order to answer three research questions: What is the meaning of sustainable development in Portland, Oregon, as it pertains to …

Status Of Nutria (Myocastor Coypus) Populations In The Pacific Northwest And Development Of Associated Control And Management Strategies, With An Emphasis On Metropolitan Habitats, Trevor Robert Sheffels

Dissertations and Theses

The nutria (Myocastor coypus) is a semi-aquatic rodent native to South America that was introduced to the Pacific Northwest, USA, in the 1930s. Primary damage categories from this invasive species include burrowing and herbivory, resulting in habitat degradation. Nutria have become well-established in metropolitan habitats, and anecdotal information suggests the problem has increased in recent years. However, little regional research on the species has been conducted. The scope of this research, which emphasizes metropolitan habitats, includes three primary foci in relation to nutria populations in the Pacific Northwest: modeling habitat suitability, assessing activity and movement patterns, and identifying and managing …

Effects Of Molecular Structure Of The Oxidation Products Of Reactive Atmospheric Hydrocarbons On The Formation Of Secondary Organic Particulate Matter, Including The Effects Of Water, Negar Niakan

Dissertations and Theses

Organic aerosols have significant effects on human health, air quality and climate. Secondary organic aerosols (SOA) are produced by the oxidation of primary-volatile organic compounds (VOC). For example, α-pinene reacts with oxidants such as hydroxyl radical (OH), ozone (O₃), and nitrate radical (NO₃), accounting for a significant portion of total organic aerosol in the atmosphere. Experimental studies have shown that the oxidation process between α-pinene and ozone has the most significant impact in the formation of SOA (Hoffmann et al., 1997). Most of the models used to predict SOA formation, however, are limited in that they …

Characterization Of Nano-Scale Aluminum Oxide Transport Through Porous Media, Sasha Norien Norwood

Dissertations and Theses

Land application of biosolids has become common practice in the United States as an alternative to industrial fertilizers. Although nutrient rich, biosolids have been found to contain high concentrations of emerging contaminants (e.g. pharmaceuticals, personal care products) while containing a significant fraction of inorganic nano-scale colloidal materials such as oxides of iron, titanium, and aluminum.

Given their reactivity and small size, there are many questions concerning the potential migration of these nano-sized colloidal materials through the soil column and into our surface and groundwater bodies. Transport of emerging pollutants of concern through the soil column, at minimum, is impacted by …

Development Of Dynamic Thermal Performance Metrics For Eco-Roof Systems, Seth Sinclair Moody

Dissertations and Theses

In order to obtain credit for an eco-roof in building energy load calculations the steady state and time-varying thermal properties (thermal mass with evapotranspiration) must be fully understood. The following study presents results of experimentation and modeling in an effort to develop dynamic thermal mass performance metrics for eco-roof systems. The work is focused on understanding the thermal parameters (foliage & soil) of an eco-roof, further validation of the EnergyPlus Green Roof Module and development of a standardized metric for assessing the time-varying thermal benefits of eco-roof systems that can be applied across building types and climate zones. Eco-roof foliage, …